main/teximage: Even on failure use valid format for init()

Otherwise init_teximage_fields_ms() (called by
_mesa_init_teximage_fields()) will always assert as it can't
find valid base format.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>

src/mesa/main/teximage.c

@@ -5772,7 +5772,7 @@ texture_image_multisample(struct gl_context *ctx, GLuint dims,
              * like, but being tidy is good.
              */
             _mesa_init_teximage_fields(ctx, texImage,
-                  0, 0, 0, 0, GL_NONE, MESA_FORMAT_NONE);
+                  0, 0, 0, 0, internalformat, texFormat);
          }
       }