checkpatch: remove GCC_BINARY_CONSTANT warning

This warning was there to avoid the use of 0bxxx values as they are not
supported by gcc prior to v4.3

Since cafa0010

 ("Raise the minimum required gcc version to 4.6"),
it's not an issue anymore and using such values can increase readability
of code.

Joe said:

: Seems sensible as the other compilers also support binary literals from
: relatively old versions.
: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3472.pdf
: https://software.intel.com/en-us/articles/c14-features-supported-by-intel-c-compiler

Link: http://lkml.kernel.org/r/392eeae782302ee8812a3c932a602035deed1609.1535351453.git.christophe.leroy@c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>