BUILD: threads: Rename SPIN/RWLOCK macros using HA_ prefix

This remove any name conflicts, especially on Solaris.
diff --git a/src/haproxy.c b/src/haproxy.c
index 4d4bd3b..8993b89 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2075,7 +2075,7 @@
 				if (xprt_get(XPRT_SSL) && xprt_get(XPRT_SSL)->destroy_srv)
 					xprt_get(XPRT_SSL)->destroy_srv(s);
 			}
-			SPIN_DESTROY(&s->lock);
+			HA_SPIN_DESTROY(&s->lock);
 			free(s);
 			s = s_next;
 		}/* end while(s) */
@@ -2124,8 +2124,8 @@
 
 		p0 = p;
 		p = p->next;
-		SPIN_DESTROY(&p0->lbprm.lock);
-		SPIN_DESTROY(&p0->lock);
+		HA_SPIN_DESTROY(&p0->lbprm.lock);
+		HA_SPIN_DESTROY(&p0->lock);
 		free(p0);
 	}/* end while(p) */