You should declare this as subroutine print_name(name, length) bind(C). That way you should be able to ccall it as :print_name without compiler-specific name-mangling (:julia_interface_mp_print_name_ is not portable). See e.g. the gfortran docs on interoperating with C.
I would declare this as integer(C_INT) rather than integer, in which case you can use Cint (rather than Int32) as the argument type in Julia and be sure that will work, even if the Fortran code is compiled in ILP64 mode.
Better yet, declare it as integer(C_INTPTR_T), in which case you can simply pass the size as Int (the corresponding type in Julia) and it will work on a 64-bit machine even in the unlikely event that your string is more than 2GiB in length.
You can also use the VALUE attribute for the variable, in which case you don’t need Ref in the ccall (the value is passed directly, not as a pointer).