lib/, src/: Use fgets_a() instead of its pattern

lib/, src/: Use fgets_a() instead of its pattern

Except for the updated includes, this patch has been scripted with a
semantic patch:

	$ cat ~/tmp/spatch/fgets_fgets_a.sp
	@@
	expression a, b;
	@@

	- fgets(a, countof(a), b)
	+ fgets_a(a, b)

Applied as:

	$ find lib* src -type f \
	| xargs spatch --sp-file ~/tmp/spatch/fgets_fgets_a.sp --in-place;

Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>