Better name string_cmp2.

[DanilaFe]

Seeing that it is passed as a function pointer, the _function keyword
was added to its name. Hopefully that helps.

[DanilaFe]

I wonder why the build system fails..
Testing it on my machine (which is obviously biased and bad, but all machines I have are my machines...):

➜  mac git:(master) ✗ git checkout -b test-branch
Switched to a new branch 'test-branch'
➜  mac git:(test-branch) ✗ git merge upstream/master 
Already up-to-date.
➜  mac git:(test-branch) ✗ git merge cleanup-string-cmp 
Updating 943bb57..15b5bdd
Fast-forward
 src/lib_ccx/ccx_encoders_helpers.c | 9 ++++-----
 src/lib_ccx/ccx_encoders_helpers.h | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)
➜  mac git:(test-branch) ✗ 

The build proceeds to generate a number of errors similar to

../src/lib_ccx/ccx_sub_entry_message.pb-c.h:7:10: fatal error: 'protobuf-c.h' file not found
#include "protobuf-c.h"
         ^
1 error generated.

But otherwise shows no signs of a merge conflict.

[cfsmp3]

You're missing a directory in your include list, that's all.

[canihavesomecoffee]

No regression spotted. Mergeable.