According to us, the sharp over the mordent, added almost certainly by Chopin while proofreading FE (→EE), does not change the sound, but specifies the incomplete notation of A. It is already the G minor chord in the preceding bar that suggests the further direction of the modulation; a modulation that, through the G minor key (featuring a), showed explicitly in the octave sequence in the discussed bar, and the e-g-b-d chord in the next two bars strives for the dominant chord in D minor in b. 126 (which found its eventual resolution on E major 12 bars later).
The easiest explanation for GE missing the is the engraver's oversight.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Errors in GE, Authentic corrections of FE, Inaccuracies in A
notation: Pitch