init/ramdisk: use pr_cont() at the end of ramdisk loading

Use pr_cont() at the end of ramdisk loading.  This will avoid the
rotator and an extra newline appearing in the dmesg.

Before:
  RAMDISK: Loading 2436KiB [1 disk] into ram disk... |
  done.

After:
  RAMDISK: Loading 2436KiB [1 disk] into ram disk... done.

Link: http://lkml.kernel.org/r/20180302205552.16031-1-aaro.koskinen@iki.fi


Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>