chardev: add missing line break in pr_warn

To fix super long dmesg error lines like

  CHRDEV "dummy_stm.0" major number 224 goes below the dynamic allocation rangeCHRDEV "dummy_stm.1" major number 223 goes below the dynamic allocation rangeswapper: page allocation failure: order:8, mode:0x26040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK)

After fix, it should look like

  CHRDEV "dummy_stm.0" major number 224 goes below the dynamic allocation range
  CHRDEV "dummy_stm.1" major number 223 goes below the dynamic allocation range
  swapper: page allocation failure: order:8, mode:0x26040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK)
Reported-by: Philip Li <philip.li@intel.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/char_dev.c

@@ -92,7 +92,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
 		}
 
 		if (i < CHRDEV_MAJOR_DYN_END)
-			pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range",
+			pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range\n",
 				name, i);
 
 		if (i == 0) {