mesa: prevent common string formatting security issues
Adds a compile-time error for obvious security issues like:
printf(string_var);
The proposed flage is more tolerant than -Wformat-nonliteral. Specifically, it tolerates common mesa formatting like:
static const char *shader_template = "really long string %d";
printf(shader_template, uniform_number);
The goal of this commit is to prevent bugs like Android build test failing on matrix.c