BUG/MEDIUM: checks: external checks can't change server status to UP

Mark Brooks reported an issue with external healthchecks, where servers are
never marked as UP. This is due to a typo, which flags a successful check as
CHK_RES_FAILED instead of CHK_RES_PASSED.

This bug is specific to the 1.6 branch.
diff --git a/src/checks.c b/src/checks.c
index 18faa9b..2c9958a 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -93,7 +93,7 @@
 
 	[HCHK_STATUS_PROCERR]	= { CHK_RES_FAILED,   "PROCERR",  "External check error" },
 	[HCHK_STATUS_PROCTOUT]	= { CHK_RES_FAILED,   "PROCTOUT", "External check timeout" },
-	[HCHK_STATUS_PROCOK]	= { CHK_RES_FAILED,   "PROCOK",   "External check passed" },
+	[HCHK_STATUS_PROCOK]	= { CHK_RES_PASSED,   "PROCOK",   "External check passed" },
 };
 
 static const struct analyze_status analyze_statuses[HANA_STATUS_SIZE] = {		/* 0: ignore, 1: error, 2: OK */