Fix multiple quality issues in the source

This PR fixes multiple issues in the source code to address issues raised by
tests/scripts/check-files.py. Specifically:
 * incorrect file permissions
 * missing newline at the end of files
 * trailing whitespace
 * Tabs present
 * TODOs in the souce code
diff --git a/tests/suites/test_suite_gcm.function b/tests/suites/test_suite_gcm.function
index 308e14b..3d0830e 100644
--- a/tests/suites/test_suite_gcm.function
+++ b/tests/suites/test_suite_gcm.function
@@ -35,7 +35,7 @@
     memset( tag_str, 0x00, sizeof( tag_str ) );
     memset( output, 0x00, sizeof( output ) );
     memset( tag_output, 0x00, sizeof( tag_output ) );
-    
+
     key_len = unhexify( key_str, hex_key_string );
     pt_len = unhexify( src_str, hex_src_string );
     iv_len = unhexify( iv_str, hex_iv_string );