riscv: uaccess: use 'asm goto' for put_user()

riscv: uaccess: use 'asm goto' for put_user()

With 'asm goto' we don't need to test the error etc, the exception just
jumps to the error handling directly.

Because there are no output clobbers which could trigger gcc bugs [1]
the use of asm_goto_output() macro is not necessary here. Not using
asm_goto_output() is desirable as the generated output asm will be
cleaner.

Use of the volatile keyword is redundant as per gcc 14.2.0 manual section
6.48.2.7 Goto Labels:
> Also note that an asm goto statement is always implicitly considered
  volatile.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
[Cyril Bur: Rewritten commit message]
Signed-off-by: Cyril Bur <cyrilbur@tenstorrent.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250410070526.3160847-5-cyrilbur@tenstorrent.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>