Revert "compositor-drm: Met process stuck when do GPU PM Test"

This reverts commit 7027805e95ab03f49ef58a55d68555c16083be70.

Change-Id: I6731e79ef0662ada0ecd5119a9a8c66764fe0433
diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index d170211..b0b9cdc 100644
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -2691,7 +2691,6 @@
 	drmModeAtomicReq *req = drmModeAtomicAlloc();
 	uint32_t flags = 0;
 	int ret = 0;
-	drm_magic_t magic;
 
 	if (!req)
 		return -1;
@@ -2799,11 +2798,6 @@
 		break;
 	}
 
-	/*drm master was set by systemd in PM test, try to set the master back.*/
-	if (!(drmGetMagic(b->drm.fd, &magic) == 0 &&
-			drmAuthMagic(b->drm.fd, magic) == 0)) {
-		drmSetMaster(b->drm.fd);
-	}
 	ret = drmModeAtomicCommit(b->drm.fd, req, flags, b);
 
 	/* Test commits do not take ownership of the state; return