net: rmnet_data: Change the print format for addresses

Print format %p displays the kernel address while bypassing the
kptr_restrict sysctl settings.

Change the print format for addresses from %p to %pK. If
kptr_restrict is enabled, addresses are printed as zeroes. To view
the actual addresses, disable kptr_restrict by -
echo 0 > /proc/sys/kernel/kptr_restrict

CRs-Fixed: 987054
Change-Id: Icb8ef62c8263ae7b17d6883c0e6a1c93d2156a6a
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>