Fix the build of some ATF tests.

When building various programs from a single Makefile, program-specific
variables are of the form <VAR>.<PROG>, not <VAR>_<PROG>.  Fix this
obvious typo to fix the build when WITH_TESTS=yes.

I am not sure how this ever worked before given that manual inspection
of bsd.progs.mk clearly shows that the expected character between the
two components is a dot and not an underscore... but I suspect the
changes in r258095 exposed this oddity.

Approved by:	rpaulo (mentor)

lib/atf/libatf-c++/tests/Makefile

@@ -23,7 +23,7 @@ FILES+=		unused_test.cpp
 		tests_test \
 		utils_test
 ATF_TESTS_CXX+=	${_T}
-SRCS_${_T}=	${_T}.cpp test_helpers.cpp
+SRCS.${_T}=	${_T}.cpp test_helpers.cpp
 .endfor
 
 ATF_TESTS_SH=	pkg_config_test
@@ -41,7 +41,7 @@ ATF_TESTS_SH=	pkg_config_test
 		text_test \
 		ui_test
 ATF_TESTS_CXX+=	${_T}
-SRCS_${_T}=	${_T}.cpp test_helpers.cpp
+SRCS.${_T}=	${_T}.cpp test_helpers.cpp
 .endfor
 
 .include <atf.test.mk>

lib/atf/libatf-c/tests/Makefile

@@ -33,7 +33,7 @@ FILES+=		unused_test.c
 		tp_test \
 		utils_test
 ATF_TESTS_C+=	${_T}
-SRCS_${_T}=	${_T}.c test_helpers.c
+SRCS.${_T}=	${_T}.c test_helpers.c
 .endfor
 
 ATF_TESTS_SH=	pkg_config_test
@@ -51,12 +51,12 @@ ATF_TESTS_SH=	pkg_config_test
 		text_test \
 		user_test
 ATF_TESTS_C+=	${_T}
-SRCS_${_T}=	${_T}.c test_helpers.c
+SRCS.${_T}=	${_T}.c test_helpers.c
 .endfor
 
 PROGS+=		process_helpers
-SRCS_process_helpers=	process_helpers.c
-MAN_process_helpers=	# defined
-BINDIR_process_helpers=	${TESTSDIR}
+SRCS.process_helpers=	process_helpers.c
+MAN.process_helpers=	# defined
+BINDIR.process_helpers=	${TESTSDIR}
 
 .include <atf.test.mk>

lib/atf/tests/test-programs/Makefile

@@ -13,7 +13,7 @@ CFLAGS+=	-I${ATF}
 ATF_TESTS_C=		c_helpers
 
 ATF_TESTS_CXX=		cpp_helpers
-SRCS_cpp_helpers=	cpp_helpers.cpp
+SRCS.cpp_helpers=	cpp_helpers.cpp
 
 ATF_TESTS_SH=		sh_helpers
 .for _T in config_test expect_test fork_test meta_data_test result_test srcdir_test