Use H5_ATOMIC macros in H5VL #58

Job	Run time
build-and-test (--enable-api-tests, --enable-multithread --disable-hl, production)	9m 59s
build-and-test (--enable-api-tests, --enable-multithread --disable-hl, debug)	12m 9s
build-and-test (--enable-api-tests, --disable-multithread --enable-threadsafe --disable-hl, produ...	8m 2s
build-and-test (--enable-api-tests, --disable-multithread --enable-threadsafe --disable-hl, debug)	8m 58s
build-and-test (--enable-api-tests, --disable-multithread --disable-threadsafe, production)	13m 2s
build-and-test (--enable-api-tests, --disable-multithread --disable-threadsafe, debug)	14m 23s
build-and-test (--disable-api-tests, --enable-multithread --disable-hl, production)	9m 20s
build-and-test (--disable-api-tests, --enable-multithread --disable-hl, debug)	10m 32s
build-and-test (--disable-api-tests, --disable-multithread --enable-threadsafe --disable-hl, prod...	7m 34s
build-and-test (--disable-api-tests, --disable-multithread --enable-threadsafe --disable-hl, debug)	8m 51s
build-and-test (--disable-api-tests, --disable-multithread --disable-threadsafe, production)	12m 52s
build-and-test (--disable-api-tests, --disable-multithread --disable-threadsafe, debug)	14m 22s
	2h 10m 4s

Provide feedback