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: I40f23300f54e7d44ae069dd190d07a69a01864f2
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/configure.ac b/configure.ac
index 0cb8a84..9cf54c9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -20,24 +20,19 @@
 AX_CXX_COMPILE_STDCXX_17([noext])
 
 # Checks for libraries.
-AX_PKG_CHECK_MODULES([SYSTEMD], [], [libsystemd >= 221], [],\
-[AC_MSG_ERROR(["Systemd version should be greater then 221."])])
+AX_PKG_CHECK_MODULES([SYSTEMD], [], [libsystemd >= 221])
 
-AX_PKG_CHECK_MODULES([SDBUSPLUS], [sdbusplus], [], [],\
-[AC_MSG_ERROR(["Requires sdbusplus package."])])
-
+AX_PKG_CHECK_MODULES([SDBUSPLUS], [sdbusplus], [])
 
 AC_PATH_PROG([SDBUSPLUSPLUS], [sdbus++])
 
-AX_PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [], [phosphor-logging], [],\
-[AC_MSG_ERROR(["Requires phosphor-logging package."])])
+AX_PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [], [phosphor-logging])
 
 # Checks for header files.
 AC_CHECK_HEADER(systemd/sd-bus.h, ,\
 [AC_MSG_ERROR([Could not find systemd/sd-bus.h...systemd development package required])])
 
-AX_PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [], [phosphor-dbus-interfaces],\
-[], [AC_MSG_ERROR(["phosphor-dbus-interfaces required and not found."])])
+AX_PKG_CHECK_MODULES([PHOSPHOR_DBUS_INTERFACES], [], [phosphor-dbus-interfaces])
 
 AC_CHECK_HEADERS([net-snmp/net-snmp-config.h],,\
     AC_MSG_ERROR(["Requires net-snmp headers"]))