util: Get program name based on path when possible

util: Get program name based on path when possible

Some programs start with the path and command line arguments in
argv[0] (program_invocation_name). Chromium is an example of
an application using mesa that does this.

This tries to query the real path for the symbolic link /proc/self/exe
to find the program name instead. It only uses the realpath if it
was a prefix of the invocation to avoid breaking wine programs.

Cc: Timothy Arceri <tarceri@itsqueeze.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>