PCI: endpoint: Use sysfs_emit() in "show" functions

Convert sprintf() in sysfs "show" functions to sysfs_emit() in order to
check for buffer overruns in sysfs outputs.

Link: https://lore.kernel.org/r/1630472957-26857-1-git-send-email-hayashi.kunihiko@socionext.com


Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>