ospfd: Some small tweaks to the SPF execution reason patch

* ospf_spf.h: use an enum for the reason, and have it as a new argument to
  ospf_spf_calculate_schedule, no need for additional call, and let compiler
  do the checking.
* ospf_spf.c: format changes - Quagga coding style places function names
  at the start of a new line, for easy grepping for definition.
  (ospf_spf_calculate_timer) Change the log format of SPF execution time to
  avoid ginormous line, and make logging conditional, as is the norm.
diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index 31cbaae..94c31c9 100644
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -2409,10 +2409,7 @@
       ospf_refresher_register_lsa (ospf, new);
     }
   if (rt_recalc)
-    {
-      ospf_flag_spf_reason (SPF_FLAG_ROUTER_LSA_INSTALL);
-      ospf_spf_calculate_schedule (ospf);
-    }
+    ospf_spf_calculate_schedule (ospf, SPF_FLAG_ROUTER_LSA_INSTALL);
   return new;
 }
 
@@ -2446,10 +2443,7 @@
       ospf_refresher_register_lsa (ospf, new);
     }
   if (rt_recalc)
-    {
-      ospf_flag_spf_reason (SPF_FLAG_NETWORK_LSA_INSTALL);
-      ospf_spf_calculate_schedule (ospf);
-    }
+    ospf_spf_calculate_schedule (ospf, SPF_FLAG_NETWORK_LSA_INSTALL);
 
   return new;
 }
@@ -2472,8 +2466,7 @@
       /* This doesn't exist yet... */
       ospf_summary_incremental_update(new); */
 #else /* #if 0 */
-      ospf_flag_spf_reason (SPF_FLAG_SUMMARY_LSA_INSTALL);
-      ospf_spf_calculate_schedule (ospf);
+      ospf_spf_calculate_schedule (ospf, SPF_FLAG_SUMMARY_LSA_INSTALL);
 #endif /* #if 0 */
  
     }
@@ -2504,8 +2497,7 @@
 	 - RFC 2328 Section 16.5 implies it should be */
       /* ospf_ase_calculate_schedule(); */
 #else  /* #if 0 */
-      ospf_flag_spf_reason (SPF_FLAG_ASBR_SUMMARY_LSA_INSTALL);
-      ospf_spf_calculate_schedule (ospf);
+      ospf_spf_calculate_schedule (ospf, SPF_FLAG_ASBR_SUMMARY_LSA_INSTALL);
 #endif /* #if 0 */
     }
 
@@ -3027,8 +3019,7 @@
 	    ospf_ase_incremental_update (ospf, lsa);
             break;
           default:
-	    ospf_flag_spf_reason (SPF_FLAG_MAXAGE);
-	    ospf_spf_calculate_schedule (ospf);
+	    ospf_spf_calculate_schedule (ospf, SPF_FLAG_MAXAGE);
             break;
           }
 	ospf_lsa_maxage (ospf, lsa);