glsl: Resolve GCC sign-compare warning.

glsl: Resolve GCC sign-compare warning.

mesa/src/glsl/nir/nir_lower_tex_projector.c: In function 'nir_lower_tex_projector_block':
mesa/src/glsl/nir/nir_lower_tex_projector.c:63:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for (int i = 0; i < tex->num_srcs; i++) {
                         ^
mesa/src/glsl/nir/nir_lower_tex_projector.c: In function 'nir_lower_tex_projector_block':
mesa/src/glsl/nir/nir_lower_tex_projector.c:114:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for (int i = proj_index + 1; i < tex->num_srcs; i++) {
                                      ^
mesa/src/glsl/nir/nir_lower_tex_projector.c: In function 'nir_lower_tex_projector_block':
mesa/src/glsl/nir/nir_lower_tex_projector.c:53:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       for (proj_index = 0; proj_index < tex->num_srcs; proj_index++) {
                                       ^
mesa/src/glsl/nir/nir_lower_tex_projector.c:57:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       if (proj_index == tex->num_srcs)
                      ^
mesa/src/glsl/nir/nir_search.c: In function 'match_value':
mesa/src/glsl/nir/nir_search.c:84:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i = 0; i < num_components; ++i)
                      ^
mesa/src/glsl/nir/nir_search.c: In function 'match_value':
mesa/src/glsl/nir/nir_search.c:110:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
          for (int i = 0; i < num_components; ++i) {
                            ^
mesa/src/glsl/nir/nir_search.c: In function 'match_value':
mesa/src/glsl/nir/nir_search.c:139:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i < num_components)
                   ^
mesa/src/glsl/nir/nir_opt_peephole_ffma.c: In function 'get_mul_for_src':
mesa/src/glsl/nir/nir_opt_peephole_ffma.c:130:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (unsigned i = 0; i < num_components; i++)
                           ^

Signed-off-by: Rhys Kidd <rhyskidd@gmail.com>
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Reviewed-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>