The two words are exchanged so routinely in English writing that the substitution has stopped looking like a claim. It is one, and it is false.
Salvation has a shape. There is a peril, there is a rescuer, and there is someone rescued who could not have managed it alone. The Christian doctrine fills those slots with sin and its penalty, with Christ, and with the sinner. Remove any of the three and the word stops meaning what it means.
Moksha fills none of them.
No rescuer
In the dominant Hindu accounts nobody comes to get you. Advaita is the extreme case: liberation is the recognition of an identity between the self and ultimate reality that was true the entire time, so strictly nothing is attained, nothing arrives, and no one intervenes. What ends is a mistake. Even the theistic schools that do have a gracious Lord, Ramanuja's, Madhva's, are describing a relationship entered, not a rescue from a penalty.
Nothing is forgiven
The obstacle is avidya, ignorance: a misapprehension of what is the case. It is not guilt, and it is not incurred before a judge. There is accordingly nothing to pardon, and no pardon in the doctrine. A tradition whose central term is knowledge is not a variant of one whose central term is acquittal.
The disagreement is internal, and it is wider
The schools differ from each other more than any of them differs from the Christian doctrine. Advaita says the liberated self was never separate. Vishishtadvaita says it remains distinct and enjoys communion. Dvaita says the difference is unqualified and adds, unusually, that some souls are bound forever. Samkhya says there is no union at all, only the isolation of consciousness from matter, and needs no God to explain it.
A single English word laid over that is not a translation. It is a decision to stop looking.
What the error costs
Two things. It makes Hinduism look like Christianity with the names changed, which is flattering to nobody and informative about nothing. And it conceals the genuinely interesting fact, which is that the comparison the traditions themselves have argued about for two thousand years is not with Christianity at all but with Buddhism, over whether there is a self to be liberated.