snmplib/system.c: make the test for return code from uname conform to POSIX.
diff --git a/snmplib/system.c b/snmplib/system.c
index b6de145..cc7cf3c 100644
--- a/snmplib/system.c
+++ b/snmplib/system.c
@@ -1318,9 +1318,9 @@
                     const char *ospmrelprefix)
 {
 #if HAVE_SYS_UTSNAME_H
-static int printOSonce = 1;
+  static int printOSonce = 1;
   struct utsname utsbuf;
-  if ( 0 != uname(&utsbuf))
+  if ( 0 > uname(&utsbuf))
     return -1;
 
   if (printOSonce) {