fwts: uefi: uefivarinfo: double free error

Coverity Scan detected a double free introduced in fix 728cbed162d88306e5fb10623fb37b282e21f73f

** CID 1240201: Double free (USE_AFTER_FREE)
/src/uefi/uefivarinfo/uefivarinfo.c: 160 in do_checkvariables()

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*** CID 1240201: Double free (USE_AFTER_FREE)
/src/uefi/uefivarinfo/uefivarinfo.c: 160 in do_checkvariables()
154 free(data);
155 return FWTS_ERROR;
156 }
157 }
158 }
159
>>> CID 1240201: Double free (USE_AFTER_FREE)
>>> Calling "free" frees pointer "data" which has already been freed.
160 free(data);
161
162 (*usedvarssize) += getdatasize;
163
164 };
165