Use uname -s which works everywhere

Makefile.in

@@ -19,7 +19,7 @@ all: build
 install: build
 	if [ "$(BUILD_C_LIBS)" -eq "1" ]; then make -C $(SRC_C_DIR) install; fi
 	$(PYTHON) ./setup.py install
-	if [ "$(BUILD_C_LIBS)" -eq "1" ] && [ "$(PLATFORM)" != "Cygwin" ]; then ldconfig || true; fi
+	if [ "$(BUILD_C_LIBS)" -eq "1" ] && [ $(findstring "CYGWIN", $(PLATFORM)) ]; then ldconfig || true; fi
 
 deps:
 	./deps.sh

configure.ac

@@ -41,7 +41,7 @@ AC_SUBST(BUILD_C_LIBS, $BUILD_C_LIBS)
 AC_SUBST(PYTHON, $PYTHON)
 AC_SUBST(SONAME, $SONAME)
 AC_SUBST(SOEXT, $SOEXT)
-AC_SUBST(PLATFORM, $(uname -o))
+AC_SUBST(PLATFORM, $(uname -s))
 AC_SUBST(INSTALL_OPTIONS, $INSTALL_OPTIONS)
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT