50 Cent -- Buries Hatchet With Mayweather ... 'He's My Brother'

Seems the 50 Cent vs. Floyd Mayweather feud is finally OVER -- with the two superstars coming together Wednesday night .... months after they TRASHED each other in public.

Don't forget ... these two HATED each other after a bitter falling out -- with 50 publicly saying Floyd was so dumb, he couldn't read. Mayweather called 50 irrelevant.

But last night in Vegas, the two didn't just hang out -- they took a photo together ... and 50 posted it to Instagram with the caption, "THE original MONEY TEAM, you gotta love it. My brother ready,may 2 don't get scared now."

So, beef squashed?!