More cleanup.

Make more stuff static, remove some dead code, and fix a few typos.

Change-Id: I010b0eadeaf61e2899c37014ad1e7082c70bd510
diff --git a/linker/linker.h b/linker/linker.h
index c416f81..296dcd6 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -60,7 +60,6 @@
 #define PAGE_END(x)    PAGE_START((x) + (PAGE_SIZE-1))
 
 void debugger_init();
-const char *addr_to_name(unsigned addr);
 
 /* magic shared structures that GDB knows about */
 
@@ -237,7 +236,7 @@
 soinfo *find_containing_library(const void *addr);
 const char *linker_get_error(void);
 
-unsigned soinfo_unload(soinfo *si);
+int soinfo_unload(soinfo* si);
 Elf32_Sym *soinfo_find_symbol(soinfo* si, const void *addr);
 Elf32_Sym *soinfo_lookup(soinfo *si, const char *name);
 void soinfo_call_constructors(soinfo *si);