I agree that neither of the passages you quoted are wrong.
My impression based on things you wrote earlier was that if Joseph didn't correct something in his translation, then it was unknown whether that part of the KJV had been correctly translated or not.
The issue then becomes that if eternal life depends on trying to keep all of the commandments, how can one know what those commandments are if there is no reliable translation of most Bible passages?
Most of the Bible is correct. Jesus Christ made it clear that those who keep these two commandments will have life eternal:
(New Testament | Luke 10:25 - 28)
25 ¶ And, behold, a certain lawyer stood up, and tempted him, saying, Master, what shall I do to inherit eternal life?
26 He said unto him, What is written in the law? how readest thou?
27 And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself.
28 And he said unto him, Thou hast answered right: this do, and thou shalt live.
Joseph Smith's translation of the Bible makes NO correction to these verses so they must be correct. We also have this from Jesus Christ:
(New Testament | Matthew 19:16 - 24)
16 ¶ And, behold, one came and said unto him, Good Master, what good thing shall I do, that I may have eternal life?
17 And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments.
18 He saith unto him, Which? Jesus said, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness,
19 Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself.
20 The young man saith unto him, All these things have I kept from my youth up: what lack I yet?
21 Jesus said unto him, If thou wilt be perfect, go and sell that thou hast, and give to the poor, and thou shalt have treasure in heaven: and come and follow me.
22 But when the young man heard that saying, he went away sorrowful: for he had great possessions.
23 ¶ Then said Jesus unto his disciples, Verily I say unto you, That a rich man shall hardly enter into the kingdom of heaven.
24 And again I say unto you, It is easier for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of God.
And this:
(New Testament | Mark 10:17 - 22)
17 ¶ And when he was gone forth into the way, there came one running, and kneeled to him, and asked him, Good Master, what shall I do that I may inherit eternal life?
18 And Jesus said unto him, Why callest thou me good? there is none good but one, that is, God.
19 Thou knowest the commandments, Do not commit adultery, Do not kill, Do not steal, Do not bear false witness, Defraud not, Honour thy father and mother.
20 And he answered and said unto him, Master, all these have I observed from my youth.
21 Then Jesus beholding him loved him, and said unto him, One thing thou lackest: go thy way, sell whatsoever thou hast, and give to the poor, and thou shalt have treasure in heaven: and come, take up the cross, and follow me.
22 And he was sad at that saying, and went away grieved: for he had great possessions.
Although the wording is different in each of these verses we can understand the meaning of Jesus' teachings.