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: I420f4702c9cf78af58854fba06e731e49e1ec5f2
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/configure.ac b/configure.ac
index ebd6a70..6599c9e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -22,12 +22,7 @@
 LT_LIB_DLLOAD
 
 # Checks for libraries.
-PKG_CHECK_MODULES(
-    [PHOSPHOR_LOGGING],
-    [phosphor-logging],
-    [],
-    [AC_MSG_ERROR([Could not find phosphor-logging...openbmc/phosphor-logging package required])]
-)
+PKG_CHECK_MODULES([PHOSPHOR_LOGGING], [phosphor-logging])
 PKG_CHECK_MODULES(
     [LIBIPMID],
     [libipmid],