build: pkg anti-pattern: use defaults

Use the defaults in the pkg check where the default error message is
sufficient to identify which package is missing.

Change-Id: Ifa7c986a2102fdee5d83b52dd4bbc030c43d8c7d
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/configure.ac b/configure.ac
index ecfda4e..d7e7812 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,12 +12,9 @@
 AM_PATH_PYTHON([2.7], [AC_SUBST([PYTHON], [echo "$PYTHON"])], [AC_MSG_ERROR(
     [Could not find python-2.7 installed...python-2.7 is required])])
 
-PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [phosphor-dbus-interfaces],,\
-    AC_MSG_ERROR(["Requires phosphor-dbus-interfaces package."]))
-PKG_CHECK_MODULES([SDBUSPLUS], [sdbusplus],,
-    AC_MSG_ERROR(["Requires sdbusplus package."]))
-PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [phosphor-logging],,\
-     AC_MSG_ERROR(["Requires phosphor-logging package."]))
+PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [phosphor-dbus-interfaces])
+PKG_CHECK_MODULES([SDBUSPLUS], [sdbusplus])
+PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [phosphor-logging])
 
 LT_INIT