[bootstrap-O3,fortran] add a NULL initializer to avoid a warning at -O3

[bootstrap-O3,fortran] add a NULL initializer to avoid a warning at -O3

Building with the bootstrap-O3 configuration option fails to compile
fortran/module.c due to an AFAICT false-positive warning about an
uninitialized use of a variable.

This patch adds a dummy initializer to silence it.

for  gcc/fortran/ChangeLog

	* module.c (load_omp_udrs): Initialize name.

From-SVN: r244087