perf record: Fix failed memory allocation for get_cpuid_str

perf record: Fix failed memory allocation for get_cpuid_str

In x86 architecture dependend part function get_cpuid_str() mallocs a
128 byte buffer, but does not check if the memory allocation succeeded
or not.

When the memory allocation fails, function __get_cpuid() is called with
first parameter being a NULL pointer.  However this function references
its first parameter and operates on a NULL pointer which might cause
core dumps.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180117131611.34319-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>