ELF, uapi: fixup ELF_ST_TYPE definition

This is very theoretical compile failure:

	ELF_ST_TYPE(st_info = A)

Cast will bind first and st_info will stop being lvalue:

	error: lvalue required as left operand of assignment

Given that the only use of this macro is

	ELF_ST_TYPE(sym->st_info)

where st_info is "unsigned char" I've decided to remove cast especially
given that companion macro ELF_ST_BIND doesn't use cast.

Link: https://lkml.kernel.org/r/Ymv7G1BeX4kt3obz@localhost.localdomain


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>