radv: fix radv_fixup_vertex_input_fetches()

We should check that num_channels is 4, otherwise that breaks
the world. Sorry for the short breakage.

Fixes: 4b3549c084 ("radv: reduce the number of loaded channels for vertex input fetches")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>

src/amd/vulkan/radv_nir_to_llvm.c

@@ -2072,7 +2072,7 @@ radv_fixup_vertex_input_fetches(struct radv_shader_context *ctx,
 	if (LLVMGetTypeKind(LLVMTypeOf(value)) == LLVMVectorTypeKind) {
 		unsigned vec_size = LLVMGetVectorSize(LLVMTypeOf(value));
 
-		if (num_channels == vec_size)
+		if (num_channels == 4 && num_channels == vec_size)
 			return value;
 
 		num_channels = MIN2(num_channels, vec_size);