top(1): help scan-build along a bit

Teach scan-build that some arrays are larger than zero, and thus not to
warn.

usr.bin/top/display.c

@@ -30,6 +30,7 @@
 
 #include <sys/time.h>
 
+#include <assert.h>
 #include <curses.h>
 #include <ctype.h>
 #include <stdarg.h>
@@ -203,19 +204,23 @@ int display_init(struct statics * statics)
 	/* save pointers and allocate space for names */
 	procstate_names = statics->procstate_names;
 	num_procstates = string_count(procstate_names);
+	assert(num_procstates > 0);
 	lprocstates = malloc(num_procstates * sizeof(int));
 
 	cpustate_names = statics->cpustate_names;
 
 	swap_names = statics->swap_names;
 	num_swap = string_count(swap_names);
+	assert(num_swap > 0);
 	lswap = malloc(num_swap * sizeof(int));
 	num_cpustates = string_count(cpustate_names);
+	assert(num_cpustates > 0);
 	lcpustates = malloc(num_cpustates * sizeof(int) * statics->ncpus);
 	cpustate_columns = malloc(num_cpustates * sizeof(int));
 
 	memory_names = statics->memory_names;
 	num_memory = string_count(memory_names);
+	assert(num_memory > 0);
 	lmemory = malloc(num_memory * sizeof(int));
 
 	arc_names = statics->arc_names;

usr.bin/top/machine.c

@@ -401,6 +401,7 @@ machine_init(struct statics *statics)
 		}
 	}
 	size = sizeof(long) * ncpus * CPUSTATES;
+	assert(size > 0);
 	pcpu_cp_old = calloc(1, size);
 	pcpu_cp_diff = calloc(1, size);
 	pcpu_cpu_states = calloc(1, size);