eal: fix tail blank check in --lcores argument

eal: fix tail blank check in --lcores argument

the tail blank after a group of lcore or cpu set
will make check of its end character fail.
for example: --lcores '(0-3)@(0-3)   ,(4-5)@(4-5)',
the next character after cpu set (0-3) is not ','
or '\0', which fail the check in eal_parse_lcores( ).

Fixes: 53e54bf81700 ("eal: new option --lcores for cpu assignment")
Signed-off-by: Wei Dai <wei.dai@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>