[2/3] pdh/tests: Make the test pass on Windows 2000.

[Dan Kegel]

Build fails here?

ccache gcc -c -I. -I. -I../../../include -I../../../include
-DWINE_STRICT_PROTOTYPES -DWINE_NO_NAMELESS_EXTENSION  -D_REENTRANT
-fPIC -Wall -pipe -fno-strict-aliasing -Wdeclaration-after-statement
-Wempty-body -Wstrict-prototypes -Wtype-limits -Wwrite-strings
-Wpointer-arith -Wlogical-op  -g -O0 -Werror  -o propsys.o propsys.c
pdh.c: In function ‘test_PdhAddCounterA’:
pdh.c:134: error: ‘PDH_INVALID_PATH’ undeclared (first use in this function)
pdh.c:134: error: (Each undeclared identifier is reported only once
pdh.c:134: error: for each function it appears in.)
pdh.c: In function ‘test_PdhAddCounterW’:
pdh.c:183: error: ‘PDH_INVALID_PATH’ undeclared (first use in this function)
../../../tools/make_ctests -o testlist.c propsys.c
make[1]: *** [pdh.o] Error 1