kbuild: refactor code in modpost to improve maintainability
kbuild: refactor code in modpost to improve maintainability

There were a great deal of overlap between the two functions
that check which sections may reference .init.text and .exit.text.
Factor out common check to a separate function and
sort entries in the original functions.

Signed-off-by: Sam Ravnborg <f16bed56189e249fe4ca8ed10a1ecae60e8ceac0@ravnborg.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs