Fix '#pragma acc acc [...]' typos

Small fix-up for r279627 (commit 519d7496beac32c26448c1d0eea176c90f543702)
"OpenACC 2.6 deep copy: C and C++ front-end parts".

	gcc/testsuite/
	* c-c++-common/goacc/mdc-1.c: Fix '#pragma acc acc [...]' typo.
	* c-c++-common/goacc/mdc-2.c: Likewise.
	* g++.dg/goacc/mdc.C: Likewise.
3 files changed