libelftc_dem_arm.c: Resource leak spotted by Coverity

[Ryan Long]

Upstream ticket ​https://sourceforge.net/p/elftoolchain/tickets/607

CID 1262518: Resource leak

229
   CID 1262518 (#1 of 1): Resource leak (RESOURCE_LEAK)56. leaked_storage: Variable arg going out of scope leaks the storage it points to.
230        return (rtn);
231}

CID 1262519: Resource leak

 958        if (VEC_PUSH_STR(&d->vec, "::operator ") == false)
      CID 1262529: Resource leak (RESOURCE_LEAK) [select issue]
    CID 1262519 (#1 of 1): Resource leak (RESOURCE_LEAK)18. leaked_storage: Variable to_str going out of scope leaks the storage it points to.
 959                return (false);

CID 1262529: Resource leak

 958        if (VEC_PUSH_STR(&d->vec, "::operator ") == false)
      CID 1262519: Resource leak (RESOURCE_LEAK) [select issue]
    CID 1262529 (#1 of 1): Resource leak (RESOURCE_LEAK)19. leaked_storage: Variable from_str going out of scope leaks the storage it points to.
 959                return (false);