Fix collision with libudev symbols when statically linking.

https://bugs.gentoo.org/830485
--- a/mdadm.h
+++ b/mdadm.h
@@ -1665,7 +1665,7 @@
 extern void udev_block(char *devnm);
 extern void udev_unblock(void);
 
-extern int in_initrd(void);
+extern int mdadm_in_initrd(void);
 
 struct cmap_hooks {
 	void *cmap_handle;      /* corosync lib related */
--- a/mdmon.c
+++ b/mdmon.c
@@ -309,7 +309,7 @@
 		{NULL, 0, NULL, 0}
 	};
 
-	if (in_initrd()) {
+	if (mdadm_in_initrd()) {
 		/*
 		 * set first char of argv[0] to @. This is used by
 		 * systemd to signal that the task was launched from
--- a/util.c
+++ b/util.c
@@ -2219,7 +2219,7 @@
 	return 0;
 }
 
-int in_initrd(void)
+int mdadm_in_initrd(void)
 {
 	/* This is based on similar function in systemd. */
 	struct statfs s;