libctsopengl_jni: Change char* to unsigned char*

char is either signed or unsigned depending on the compiler.
If char is signed the 'readInt' function can provide erroneous results
(eg negative values) and can lead to a crash.

Change-Id: Ieec401e2c5edcae0ab261e21c7c06b6cbc0a0ff8
Signed-off-by: Adriana Reus <adriana.reus@intel.com>
1 file changed