library: exploit enhanced library memory allocation provisions

There were numerous library memory allocation inconsistencies.
Some were checked for failure and others were not.

All library source modules were modified to utilize the alloc.h
memory rouines which are consistent in dealing with errors.

proc/slab.c

@@ -18,6 +18,7 @@
 
 #include "slab.h"
 #include "procps.h"
+#include "alloc.h"
 
 #define SLABINFO_LINE_LEN	2048
 #define SLABINFO_VER_LEN	100
@@ -41,9 +42,7 @@ static struct slab_info *get_slabnode(void)
 		node = free_index;
 		free_index = free_index->next;
 	} else {
-		node = malloc(sizeof(struct slab_info));
-		if (!node)
-			perror("malloc");
+		node = xmalloc(sizeof(struct slab_info));
 	}
 
 	return node;