lib/kobject: Join string literals back

There is no need to split string literals. Moreover, it would be simpler
to grep for an actual code line, when debugging, by using almost any
part of the string literal in question.

While here, replace printk(LEVEL) by pr_lvl() macros.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>