api: Use GNU strerror_r when available

api: Use GNU strerror_r when available

GNU strerror_r is only available in glibc, musl impelents the XSI
version which is slightly different, therefore check if GNU version is
available before using it, otherwise use the XSI compliant version.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
TJH: Minor formatting change so that the line doesn't exceed 100 chars