drm: Use the type of the array element when reallocating

drm: Use the type of the array element when reallocating

Static analysers find it 'suspicious', that we're trying to allocate memory for
elements of size sizeof(struct drm_fb_helper_connector) when the array is
defined as struct drm_fb_helper_connector **.

Use sizeof(struct drm_fb_helper_connector *) instead.

Note that the structure being defined as:

struct drm_fb_helper_connector {
	struct drm_connector *connector;
};

This was still doing the right thing, but may not in the future if
additional fields are added.

Cc: Todd Previte <tprevite@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>