Fixes these GCC warnings.
gallivm/lp_bld_sample_aos.c: In function 'lp_build_sample_image_nearest':
gallivm/lp_bld_sample_aos.c:271: warning: 't_ipart' may be used uninitialized in this function
gallivm/lp_bld_sample_aos.c:271: warning: 'r_ipart' may be used uninitialized in this function
LLVMTypeRef i32_vec_type, h16_vec_type, u8n_vec_type;
LLVMValueRef i32_c8;
LLVMValueRef width_vec, height_vec, depth_vec;
- LLVMValueRef s_ipart, t_ipart, r_ipart;
+ LLVMValueRef s_ipart, t_ipart = NULL, r_ipart = NULL;
LLVMValueRef x_stride;
LLVMValueRef x_offset, offset;
LLVMValueRef x_subcoord, y_subcoord, z_subcoord;