platform/x86: thinkpad_acpi: Join string literals back

There is no point to keep string literal split. It even makes slightly
harder to maintain and debug.

Join string literals back to be oneliners.

While here, print negative error without changing a sign as it is a
common pattern in the kernel.

Other than above there were no functional changes intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>