hidtest: don't use a C++ source file, since it's pure C

This allows to build the test program with toolchains that don't have
C++ support.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

hidtest/Makefile.am

@@ -4,17 +4,17 @@ AM_CPPFLAGS = -I$(top_srcdir)/hidapi/
 if OS_LINUX
 noinst_PROGRAMS = hidtest-libusb hidtest-hidraw
 
-hidtest_hidraw_SOURCES = hidtest.cpp
+hidtest_hidraw_SOURCES = hidtest.c
 hidtest_hidraw_LDADD = $(top_builddir)/linux/libhidapi-hidraw.la
 
-hidtest_libusb_SOURCES = hidtest.cpp
+hidtest_libusb_SOURCES = hidtest.c
 hidtest_libusb_LDADD = $(top_builddir)/libusb/libhidapi-libusb.la
 else
 
 # Other OS's
 noinst_PROGRAMS = hidtest
 
-hidtest_SOURCES = hidtest.cpp
+hidtest_SOURCES = hidtest.c
 hidtest_LDADD = $(top_builddir)/$(backend)/libhidapi.la
 
 endif

windows/hidtest.vcproj

@@ -174,7 +174,7 @@
 			UniqueIdentifier="{4FC737F1-C7A5-4376-A066-2A32D752A2FF}"
 			>
 			<File
-				RelativePath="..\hidtest\hidtest.cpp"
+				RelativePath="..\hidtest\hidtest.c"
 				>
 			</File>
 		</Filter>