cogl: fix compile error caused by -Werror=maybe-uninitialized
When enable DEBUG_BUILD, cogl compile failed with error:
| ../../cogl-1.22.2/cogl/driver/gl/gles/cogl-driver-gles.c:217:17: error: 'gltype' may be used uninitialized in this function [-Werror=maybe-uninitialized]
| *out_gltype = gltype;
| ~~~~~~~~~~~~^~~~~~~~
| ../../cogl-1.22.2/cogl/driver/gl/gles/cogl-driver-gles.c:213:22: error: 'glintformat' may be used uninitialized in this function [-Werror=maybe-uninitialized]
| *out_glintformat = glintformat;
| ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
Source: https://gitlab.gnome.org/GNOME/cogl/blob/master/cogl/driver/gl/gles/cogl-driver-gles.c
it can handle correctly, so fix with -Wnoerror
Signed-off-by: Changqing Li <changqing.li@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
