ANDROID: cpufreq: times: convert freq_table to flexible array member

Since commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3")
we get a runtime 'UBSAN array index out of bounds' error, because the
code here is now trying to access an array past its 0 number of
elements.

Replace old-style 0-element array "freq_table" in struct cpu_freqs with
modern C99 flexible array.

While at it, convert to using struct_size() instead of manually
calculating array sizes.

Test: TH
Bug: 292213903
Change-Id: I66ee3f733bc5da4c86a0684858cb2767840657d7
Signed-off-by: André Draszik <draszik@google.com>

drivers/cpufreq/cpufreq_times.c

@@ -35,7 +35,7 @@ struct cpu_freqs {
 	unsigned int offset;
 	unsigned int max_state;
 	unsigned int last_index;
-	unsigned int freq_table[0];
+	unsigned int freq_table[];
 };
 
 static struct cpu_freqs *all_freqs[NR_CPUS];
@@ -176,8 +176,7 @@ void cpufreq_times_create_policy(struct cpufreq_policy *policy)
 	cpufreq_for_each_valid_entry(pos, table)
 		count++;
 
-	tmp =  kzalloc(sizeof(*freqs) + sizeof(freqs->freq_table[0]) * count,
-		       GFP_KERNEL);
+	tmp = kzalloc(struct_size(freqs, freq_table, count), GFP_KERNEL);
 	if (!tmp)
 		return;