Linux 6.1 compat: change order of sys/mutex.h includes

After Linux 6.1-rc1 came out, the build started failing to build a
couple of the files in the linux spl code due to the mutex_init
redefinition. Moving the sys/mutex.h include to a lower position within
these two files appears to fix the problem.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #14040

module/os/linux/spl/spl-procfs-list.c

@@ -23,9 +23,9 @@
  */
 
 #include <sys/list.h>
-#include <sys/mutex.h>
 #include <sys/procfs_list.h>
 #include <linux/proc_fs.h>
+#include <sys/mutex.h>
 
 /*
  * A procfs_list is a wrapper around a linked list which implements the seq_file