gir: Fix parser warning due to empty line
The GIR parser does not want any empty line after the function or macro name line.
Fixes the following warning:
[309/4246] Generating Gst-1.0.gir with a custom command
../subprojects/gstreamer/gst/gstelement.h:57: Warning: Gst: "@element" parameter unexpected at this location:
* @element: The element name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gstelement.h:84: Warning: Gst: "@e" parameter unexpected at this location:
* @e: The element name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gstelement.h:106: Warning: Gst: "@e" parameter unexpected at this location:
* @e: The element name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gstdeviceprovider.h:32: Warning: Gst: "@d_p" parameter unexpected at this location:
* @d_p: The device provider name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gstdynamictypefactory.h:28: Warning: Gst: "@t_n" parameter unexpected at this location:
* @t_n: The dynamic type name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gsttypefind.h:34: Warning: Gst: "@type_find" parameter unexpected at this location:
* @type_find: The type find name in lower case, with words separated by '_'.
^
../subprojects/gstreamer/gst/gsttypefind.h:61: Warning: Gst: "@t_f" parameter unexpected at this location:
* @t_f: The type find name in lower case, with words separated by '_'.
cc @gdesmott @dabrain34 ^