drm/vmwgfx: Replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct vmw_view.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

This results in no differences in binary output.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/254
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Reviewed-by: Kees Cook <[e-mail]>
Reviewed-by: Zack Rusin <[e-mail]>
Signed-off-by: Gustavo A. R. Silva <[e-mail]>

drivers/gpu/drm/vmwgfx/vmwgfx_so.c

···
 	unsigned view_id;              /* Immutable */
 	u32 cmd_size;                  /* Immutable */
 	bool committed;                /* Protected by binding_mutex */
-	u32 cmd[1];                    /* Immutable */
+	u32 cmd[];		       /* Immutable */
 };
 
 static int vmw_view_create(struct vmw_resource *res);