library: eliminate all dependencies on alloc.h/alloc.c

While that old master branch library may utilize those
memory allocation functions found in the alloc module,
it was inappropriate for this newlib branch to subject
callers to a stderr message followed by an early exit.

Of course, the old libprocps offered a message handler
override provision (xalloc_err_handler) but that, too,
would seem to be inappropriate for our modern library.

[ remember the battles fought with that damn libnuma ]

So, this commit will tweak those old inherited sources
setting the stage for standardized return values/errno
settings in connection with a memory allocation error.

------------------------------------------------------
Along the way, we'll address the following miscellany:

. Completely eliminate usage of anything from alloc.h.
This, of course, entails our own error checking of the
alternative allocation calls from stdlib.h & string.h.

. Eliminate use of the strdup function where possible,
as with 'procps_uptime' and 'procps_loadavg' routines.

. Whack some obsolete code (getslabinfo) in sysinfo.c.

Signed-off-by: Jim Warner <james.warner@comcast.net>

proc/devname.c

@@ -26,7 +26,6 @@
 #include <unistd.h>
 #include "version.h"
 #include "devname.h"
-#include "alloc.h"
 
 // This is the buffer size for a tty name. Any path is legal,
 // which makes PAGE_SIZE appropriate (see kernel source), but
@@ -83,7 +82,8 @@ static void load_drivers(void){
     end = strchr(p, ' ');
     if(!end) continue;
     len = end - p;
-    tmn = xcalloc(sizeof(tty_map_node));
+    if (!(tmn = calloc(1, sizeof(tty_map_node))))
+       goto fail;
     tmn->next = tty_map;
     tty_map = tmn;
     /* if we have a devfs type name such as /dev/tts/%d then strip the %d but