x86/uaccess: Fix up the fixup

New tooling got confused about this:

  arch/x86/lib/memcpy_64.o: warning: objtool: .fixup+0x7: return with UACCESS enabled

While the code isn't wrong, it is tedious (if at all possible) to
figure out what function a particular chunk of .fixup belongs to.

This then confuses the objtool uaccess validation. Instead of
returning directly from the .fixup, jump back into the right function.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>