Move MAXDEPTH symbol to lib66.so

Prevent symbol lookup error in commands linked to lib66.so:

66-tree: symbol lookup error: /usr/x86_64-pc-linux-gnu/lib/lib66.so.0.2:
undefined symbol: MAXDEPTH

src/66/66-inservice.c

@@ -47,7 +47,6 @@
 
 static unsigned int REVERSE = 0 ;
 static unsigned int NOFIELD = 1 ;
-unsigned int MAXDEPTH = 1 ;
 static unsigned int GRAPH = 0 ;
 static char const *const *ENVP ;
 static unsigned int nlog = 20 ;

src/66/66-intree.c

@@ -42,7 +42,6 @@
 
 static unsigned int REVERSE = 0 ;
 static unsigned int NOFIELD = 1 ;
-unsigned int MAXDEPTH = 1 ;
 static unsigned int GRAPH = 0 ;
 static uid_t OWNER ;
 static char OWNERSTR[UID_FMT] ;

src/lib66/ss_info_utils.c

@@ -31,6 +31,8 @@
 
 #include <66/resolve.h>
 
+unsigned int MAXDEPTH = 1 ;
+
 ss_resolve_graph_style graph_utf8 = {
 	UTF_VR UTF_H,
 	UTF_UR UTF_H,