lib/find_bit.c: uninline helper _find_next_bit()

It saves 25% of .text for arm64, and more for BE architectures.

Before:
  $ size lib/find_bit.o
     text    data     bss     dec     hex filename
     1012      56       0    1068     42c lib/find_bit.o

After:
  $ size lib/find_bit.o
     text    data     bss     dec     hex filename
      776      56       0     832     340 lib/find_bit.o

Link: http://lkml.kernel.org/r/20200103202846.21616-3-yury.norov@gmail.com


Signed-off-by: Yury Norov <yury.norov@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>