Fortran: fix error recovery on bad structure constructor in DATA statement

gcc/fortran/ChangeLog:

	PR fortran/67804
	* primary.c (gfc_match_structure_constructor): Recover from errors
	that occurred while checking for a valid structure constructor in
	a DATA statement.

gcc/testsuite/ChangeLog:

	PR fortran/67804
	* gfortran.dg/pr93604.f90: Adjust to changed diagnostics.
	* gfortran.dg/pr67804.f90: New test.