libvpd: String related fixes
libvpd: String related fixes

Changed variable type to size_t, as string.find returns size_t. Added error
condition and logged, when string format is not proper e.g :"xy"..."xyz"..."a
, -> string not terminated correctly. Another case: string is :"xy"..."xyz"...
, but str_ps = 3, which is not valid. Removed unwanted variable. Replaced do
while with while loop, as do while had bug returning string at position 0 and 1.
VPD logging macro is been used here.

Signed-off-by: Ankit Kumar <7d7f3b0de32b6cc2e9608ebf7986c26b5954d288@linux.vnet.ibm.com>
[Added empty line validation and fixed trivial coding style issue - Vasant]
Signed-off-by: Vasant Hegde <a6d753843573f7bfed5075c1e875b0be8007a0ab@linux.vnet.ibm.com>

kamalesh-babulal/libvpd,kamalesh-babulal/libvpd,kamalesh-babulal/libvpd