MIPS: Drop #ifdef __ELF__ in definition of LEAF_MIPS32R2

MIPS: Drop #ifdef __ELF__ in definition of LEAF_MIPS32R2

Commit 6d2cf40166d8 ("MIPS: Fix exported symbols in public API") attempted to
add a .hidden assembly directive, conditional on the code being compiled for an
ELF target. Unfortunately the #ifdef added was already inside a macro and
wasn't expanded properly by the preprocessor.

Fix by removing the check. It's unlikely there are many non-ELF MIPS systems
around anyway.

Fixes: Bug 83358 (https://bugs.freedesktop.org/83358)
Fixes: 6d2cf40166d8 ("MIPS: Fix exported symbols in public API")
Signed-off-by: James Cowgill <james410@cowgill.org.uk>
Cc: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Cc: Nemanja Lukic <nemanja.lukic@rt-rk.com>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>