[PATCH] cpu: maxfreq: fix build errors on arm32 + gcc10

[Alex Hung]

The below errors were observed on armhf with Groovy and Hirsute
cpu/maxfreq/maxfreq.c:28:23: error: ‘%s’ directive output may be
truncated writing between 3 and 2147483645 bytes into a region of
size 4072 [-Werror=format-truncation=]
   28 | #define CPU_FREQ_PATH "/sys/devices/system/cpu"
      |                       ^~~~~~~~~~~~~~~~~~~~~~~~~
cpu/maxfreq/maxfreq.c:143:4: note: in expansion of macro ‘CPU_FREQ_PATH’
  143 |    CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
      |    ^~~~~~~~~~~~~
cpu/maxfreq/maxfreq.c:143:20: note: format string is defined here
  143 |    CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
      |                    ^~

Signed-off-by: Alex Hung <alex.hung at canonical.com>
---
 src/cpu/maxfreq/maxfreq.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/cpu/maxfreq/maxfreq.c b/src/cpu/maxfreq/maxfreq.c
index 168a69e8..b0ce0fe9 100644
--- a/src/cpu/maxfreq/maxfreq.c
+++ b/src/cpu/maxfreq/maxfreq.c
@@ -139,9 +139,9 @@ static int maxfreq_test1(fwts_framework *fw)
 		    strlen(entry->d_name) < 3)
 			continue;
 
-		snprintf(path, sizeof(path),
-			CPU_FREQ_PATH "/%s/cpufreq/scaling_available_frequencies",
-			entry->d_name);
+		strncpy(path, CPU_FREQ_PATH, strlen(CPU_FREQ_PATH) + 1);
+		snprintf(path + strlen(CPU_FREQ_PATH), sizeof(path) - strlen(CPU_FREQ_PATH),
+			"/%s/cpufreq/scaling_available_frequencies", entry->d_name);
 
 		if ((data = fwts_get(path)) == NULL)
 			continue;
@@ -214,4 +214,3 @@ static fwts_framework_ops maxfreq_ops = {
 };
 
 FWTS_REGISTER("maxfreq", &maxfreq_ops, FWTS_TEST_ANYTIME, FWTS_FLAG_BATCH)
-
-- 
2.25.1