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: Icee581a37f9105bc16cc33391e822aac54728ac7
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/configure.ac b/configure.ac
index bb32ad6..2e7cbcf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -23,12 +23,9 @@
 AC_CHECK_HEADER(experimental/filesystem, [],
     [AC_MSG_ERROR([Could not find experimental/filesystem...libstdc++fs development package 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])
 
 # Code coverage
 AX_CODE_COVERAGE