dwarf: Fix warning about -Wmaybe-uninitialized.
```
src/dwarf/Gfind_proc_info-lsb.c:536:16: warning: 'eh_frame' may be used uninitialized in this function [-Wmaybe-uninitialized]
Elf_W (Addr) eh_frame;
^
```
Introduced-in:
@@ -533,7 +533,7 @@ dwarf_find_eh_frame_section(struct dl_phdr_info *info)
int fd;
Elf_W (Ehdr) ehdr;
Elf_W (Half) shstrndx;
- Elf_W (Addr) eh_frame;
+ Elf_W (Addr) eh_frame = 0;
unsigned int i;
const char *file = info->dlpi_name;
char secname[EH_FRAME_LEN];
