md, sysfs, LLVMLinux: Remove nested function from bcache sysfs

md, sysfs, LLVMLinux: Remove nested function from bcache sysfs

Replace the use of nested functions where a normal function will suffice.

Nested functions are not liked by upstream kernel developers in general. Their
use breaks the use of clang as a compiler, and doesn't make the code any
better.

This code now works for both gcc and clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Forward-ported-by: Bernhard Rosenkränzer <bero@linaro.org>
Signed-off-by: Bernhard Rosenkränzer <bero@linaro.org>